This invention relates generally to electric arc furnace practice and, more particularly, to coherent jet practice in an electric arc furnace.
A recent significant advancement in the field of gas dynamics is the development of coherent jet technology which produces a laser-like jet of gas which can travel a long distance while still retaining substantially all of its initial velocity and with very little increase to its jet diameter. One very important commercial use of coherent jet technology is in electric arc furnace practice such as for providing gas for lancing. Any improvement in coherent jet practice in conjunction with electric arc furnace operation would be very desirable.
Accordingly it is an object of this invention to provide a system wherein coherent jet practice and other operations of an electric arc furnace may be carried out with greater effectiveness.
The above and other objects, which will become apparent to those skilled in the art upon a reading of this disclosure, are attained by the present invention, one aspect of which is:
A quadrilateral assembly suitable for installation into a wall of an electric arc furnace comprising a coherent jet opening for providing a coherent jet of gas at a first downward angle into the electric arc furnace, a carbon injection nozzle below and/or to the side of the coherent jet opening, and at least one post combustion nozzle for providing at least one oxidant stream into the electric arc furnace, said oxidant stream(s) being at a second downward angle which is shallower than said first downward angle.
Another aspect of the invention is:
A quadrilateral assembly suitable for installation into a wall of an electric arc furnace comprising a coherent jet opening for providing a coherent jet of gas at a downward angle into the electric arc furnace, a carbon injection nozzle below and/or to the side of the coherent jet opening, and a plurality of post combustion nozzles for providing a plurality of oxidant streams into the electric arc furnace, said post combustion nozzles oriented such that the oxidant streams converge to form a sheet of gas within the electric arc furnace.
A further aspect of the invention is:
A method for providing gas into an electric arc furnace comprising passing a coherent jet of gas from a coherent jet opening of a quadrilateral assembly downwardly into the electric arc furnace at a first downward angle, passing a first stream of post combustion oxidant from a first post combustion nozzle of the quadrilateral assembly into the electric arc furnace at a second downward angle which is shallower than said first downward angle, passing a second stream of post combustion oxidant from a second post combustion nozzle of the quadrilateral assembly into the electric arc furnace at an angle so as to converge with the first stream of post combustion oxidant, and forming a sheet of post combustion oxidant from said first and second streams of post combustion oxidant within the electric arc furnace.
As used herein, the term xe2x80x9ccoherent jetxe2x80x9d means a stream of gas whose diameter remains substantially constant along its length. A coherent jet is typically surrounded by, i.e. is within, a flame envelope, and typically has a supersonic velocity.
As used herein, the term xe2x80x9clancingxe2x80x9d means providing gas from a gas stream above the surface of a liquid into the liquid.
As used herein, the term xe2x80x9cpost combustionxe2x80x9d means providing oxidant into an electric arc furnace for combustion with combustible matter above the surface of molten metal within the surface.